31-GP-220M

1.1 This standard applies to a corrosion removing compound, containing sodium hydroxide and sequestering agents, for immersion cleaning. 1.2 Intended Uses - The corrosion removing compound covered by this standard is meant for immersion cleaning only. It is used for removing rust and scale from iron and steel surfaces, with or without attendant paint, grease or other surface coatings, by simple immersion of the articles. The dimensional characteristics of steel or iron particles will not be altered by the use of this material. The usual concentration employed is 0.5kg/L. The compound may also be used for cleaning copper, brass, magnesium and other metals, and to strip phosphate coatings where separate solutions formulated for the purpose are not available. The compound is more effective when used at elevated temperatures for rust removal and may be heated to its boiling point. Thorough washing in clean water with prompt and thorough after-drying should follow all treatments. Treatment need not be extended beyond the point of effectiveness in removing the surface deposits. Cleaned and dried surfaces should be coated immediately with a light preservative oil, unless the treatment is to be followed by surface finishing.